Structures of the biological repeating units in the O-chain polysaccharides of Hafnia alvei strains having a typical lipopolysaccharide outer core region

• Published in: FEMS immunology and medical microbiology 2005-08, Vol.45 (2), p.269-278
• Main Authors: Katzenellenbogen, Ewa, Kocharova, Nina A., Zatonsky, George V., Shashkov, Alexander S., Bogulska, Maria, Knirel, Yuriy A.
• Format: Article
• Language: English
• Subjects: Biological repeating unit; Biosynthesis; Carbohydrate Conformation; Carbohydrate Sequence; Chromatography, Gel; Disaccharides; Gas Chromatography-Mass Spectrometry; Gel chromatography; Glucose; Hafnia alvei; Hafnia alvei - chemistry; Hafnium oxide; Lipopolysaccharide; Lipopolysaccharides; Magnetic resonance spectroscopy; Methylation; Molecular Sequence Data; Molecular Structure; Monosaccharides; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; O Antigens - chemistry; O-antigen structure; Oligosaccharides; Polysaccharides; Polysaccharides, Bacterial - chemistry; Saccharides; Strains (organisms); Substitutes
• ISSN: 0928-8244; 1574-695X; 2049-632X
• DOI: 10.1016/j.femsim.2005.05.003

Earlier, the structures of the O-chain polysaccharides of the lipopolysaccharides (LPS) of a number of Hafnia alvei strains have been established. However, it remained unknown, which is the first and the last monosaccharide of the O-chain. This is defined by the structure of the so-called biological repeating unit (O-unit), which is pre-assembled and then polymerised in the course of biosynthesis of bacterial polysaccharides by the Wzy-dependent pathway. Now we report on the structures of the O-units in 10 H. alvei strains. The LPS were cleaved by mild acid hydrolysis and oligosaccharide fractions IIIa and IIIb were isolated by gel chromatography subsequently on Sephadex G-50 and BioGel P-2 and studied by methylation analysis and NMR spectroscopy. Fraction IIIb was found to represent the core oligosaccharide containing a terminal upstream α- d-Glc-(1→3)-α- d-Glc or α- d-Gal-(1→3)-α- d-Glc disaccharide in the outer region that is typical of H. alvei. Fraction IIIa consists of the LPS core with one O-unit linked by a 3-substituted β- d-GalNAc residue (in strains PCM 1189 and PCM 1546) or a 3-substituted β- d-GlcNAc residue (in the other strains studied). In most strains examined the β-configuration of the d-GlcNAc linkage in the first O-unit attached to the core is the same and in some strains is opposite to that found in the interior O-units of the O-chain polysaccharide. Various monosaccharides, including d-Glc, d-Gal, d-GlcA and acyl derivatives of 3-amino-3,6-dideoxy- d-glucose or 4-amino-4,6-dideoxy- d-glucose, occupy the non-reducing end of the O-unit.